Guy 1: Hey you almost done I really have to take a shit!
Guy 2: Yeah, one sec I have to get rid of this anus cake.
Guy 1: WTF!?
Guy 2: My shit is half-way in my butt and half-way out!
Guy 1: *runs away*

An uncouth individual who is so detestable and despicable that the name "anus" would be unsuitable; this is the type of person who, upon thinking of them, makes you visualize an entire cake made up of nothing more than compressed dirty anuses. Hence, an anus cake.